5,834 research outputs found
Inventory of wetlands and agricultural land cover in the upper Sevier River Basin, Utah
The use of color infrared aerial photography in the mapping of agricultural land use and wetlands in the Sevier River Basin of south central utah is described. The efficiency and cost effectiveness of utilizing LANDSAT multispectral scanner digital data to augment photographic interpretations are discussed. Transparent overlays for 27 quadrangles showing delineations of wetlands and agricultural land cover were produced. A table summarizing the acreage represented by each class on each quadrangle overlay is provided
Irrigated acreage in the Bear River Basin as of the 1975 growing season
The irrigated cropland in the Bear River Basin as of the 1975 growing season was inventoried from satellite imagery. LANDSAT color infrared images (scale 1:125,000) were examined for early, mid, and late summer dates, and acreage was estimated by use of township/section overlays. The total basin acreage was estimated to be 573,435 acres, with individual state totals as follows: Idaho 234,370 acres; Utah 265,505 acres; and Wyoming 73,560 acres. As anticipated, wetland areas intermingled among cropland appears to have produced an over-estimation of irrigated acreage. According to a 2% random sample of test sites evaluated by personnel from the Soil Conservation Service such basin-wide over-estimation is 7.5%; individual counties deviate significantly from the basin-wide figure, depending on the relative amount of wetland areas intermingled with cropland
Prolactin
During an oral glucose tolerance test (OGTT) glucose and insulin levels were measured in 26 patients with prolactin-producing pituitary tumours without growth hormone excess. Basal glucose and insulin levels did not differ from the values of an age-matched control group. After glucose load the hyperprolactinaemic patients showed a decrease in glucose tolerance and a hyperinsulinaemia. Bromocriptine (CB 154), which suppressed PRL, improved glucose tolerance and decreased insulin towards normal in a second OGTT. — Human PRL or CB 154 had no significant influence on insulin release due to glucose in the perfused rat pancreas. — These findings suggest a diabetogenic effect of PRL. CB 154 might be a useful drug in improving glucose utilization in hormone-active pituitary tumours
X-ray Halos and Large Grains in the Diffuse Interstellar Medium
Recent observations with dust detectors on board the interplanetary
spacecraft Ulysses and Galileo have recorded a substantial flux of large
interstellar grains with radii between 0.25 and 2.0 mu entering the solar
system from the local interstellar cloud. The most commonly used interstellar
grain size distribution is characterized by a a^-3.5 power law in grain radii
a, and extends to a maximum grain radius of 0.25 mu. The extension of the
interstellar grain size distribution to such large radii will have a major
effect on the median grain size, and on the amount of mass needed to be tied up
in dust for a given visual optical depth. It is therefore important to
investigate whether this population of larger dust particles prevails in the
general interstellar medium, or if it is merely a local phenomenon. The
presence of large interstellar grains can be mainly inferred from their effect
on the intensity and radial profiles of scattering halos around X-ray sources.
In this paper we examine the grain size distribution that gives rise to the
X-ray halo around Nova Cygni 1992. The results of our study confirm the need to
extend the interstellar grain size distribution in the direction of this source
to and possibly beyond 2.0 mu. The model that gives the best fit to the halo
data is characterized by: (1) a grain size distribution that follows an a^-3.5
power law up to 0.50 mu, followed by an a^-4.0 extension from 0.50 mu to 2.0
mu; and (2) silicate and graphite (carbon) dust-to-gas mass ratios of 0.0044
and 0.0022, respectively, consistent with solar abundances constraints.
Additional observations of X-ray halos probing other spatial directions are
badly needed to test the general validity of this result.Comment: 17 pages, incl. 1 figure, accepted for publ. by ApJ Letter
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